Power sander attachment

ABSTRACT

An attachment is provided for heavy duty power sanders, such as the air operated types utilized in automotive body shops, which facilitates sanding the sculptured portions of a car body. The attachment consists of a generally rectangular plate faced, on its lower surface, with a resilient material and provided with spring clasps at both ends of the upper surface for clasping a sheet of abrasive paper between the resilient surface and the work surface. The attachment according to the invention departs from standard abrasive paper holding plates in that each of its long edges is turned up at an angle which, in variant embodiments, may be the same or different on each side and range from approximately 7* to 60*. The angled lips back the abrasive paper in such a manner that the sanding operation tends to follow a sculptured surface rather than bite into it.

United States Patent Morgan [4 Dec. 5, 1972 POWER SANDER ATTACHMENT Primary Examiner-Othell M. Simpson [72] Inventor: Andrew Morgan, Tolleson, Ariz. Phllhps [73] Assignee: Manuel M. Leyva, Jr., a part in- [57] 7 ABSTRACT wrest An attachment is provided for heavy duty power san- [22] Filed: Feb. 11, 1971 ders, such as the air operated types utilized in automotive body shops, which facilitates sanding the sculp- [211 App! 114587 tured portions of a car body. The attachment consists of a generally rectangular plate faced, on its lower sur- [52] US. Cl ..51/382 face, with a resilient material and provided with spring [51] Int. Cl. ..B24d 17/00 Clasps at th nds f th upper surface for clasping a [53] Fi ld f S h 51/382, 387, 392, 391, 343 sheet of abrasive paper between the resilient surface 51/170 L, 1 0 175 35g; 15 231431 and the work surface. The attachment according to the invention departs from standard abrasive paper [56] References Cited holding plates in that each of its long edges is turned up at an angle which, in variant embodiments, may be UNITED STATES PATENTS the same or different on each side and range from approximately 7 to 60. The angled lips back the abra- Ludwlck sive paper in such a manner the Sanding operation 2922l77 H1960 HudsOn "51/382 x tends to follow a sculptured surface rather than bite 3,488,897 l/1970 Taafe, Jr. ..5l/387 into it 3,571,986 3/l97l Champayne ..5 l/ 392 4 Claims, 3 Drawing Figures P'A'TENTEDM 5 I912 INVENTOR.

ANDREW MORGAN q, ATTORNEYS 1 POWER SANDER ATTACHMENT This invention relates to the power abrading arts and, more particularly, to attachments for a power sander.

Power sanders are utilized in automotive body shops to smooth repaired areas and blend the surface of repaired areas with adjacent areas until the surface is restored to the original contour and is quite smooth and uniform for receiving paint. Because of the considerable area which must be sanded with a great deal of care, power orbital and in line oscillating sanders are typically used to speed up the process. The best examples of such industrial grade sanders are air operated and consist of a power head generally centrally bolted to a flat, rectangular attachment which includes means for securely holding abrasive paper on its lower surface. These power sanders, utilizing the flat, rectangular abrasive paper holding attachment, perform their office admirably when the areas to be smoothed are flat or have only a slight, convex contour. However, most modern automobiles also have areas of a distinctly concave, even sculptured, character, and sanding these areas utilizing the prior art abrasive paper support plates often results in a digging and gouging action on the concave surface resulting from the high pressure exerted on the work surface by the plate edges which are virtually the only support areas if the concavity is sufficiently sharp. The use of a resilient material between the abrasive paper and the support plate permits the usual flat plates to accommodate a certain amount of concavity, but this facility is strictly limited to very shallow curvatures. Thus, it will be seen that it would be highly desirable to provide an abrasive paper support plate for a conventional power sander which achieves the facility for sanding sculptured areas without cutting or gouging.

It is therefore a broad subject of my invention to provide an improved abrasive paper support plate for a power sander.

It is a more specific object of my invention to provide such a support plate which facilitates the sanding of concave and sculptured areas.

It is a still more specific object of my invention to provide such a plate having raised edges for accommodating concave work surfaces.

The subject matter of the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, may best be understood by reference to the following description taken in connection with the accompanying drawing of which:

FIG. 1 is a perspective view of an exemplary embodiment of the abrasive paper support plate constituting the present invention secured to a conventional power sander;

FIG. 2 is an end view of a plate according to the present invention illustrating an exemplary asymmetrical configuration; and

FIG. 3 is an end view of a plate according to the present invention illustrating an exemplary symmetrical configuration.

Referring now to FIG. 1, it will be observed that an 6 tending upwardly through a mounting plate 4, and a nut 5 is threaded onto the bolt 3 and tightened to secure the plate 2 to the power head 1. Similar structure, out of view in FIG. 1, is provided at the rearward portion of the assembly. High pressure air is provided to the power head 1 through a flexible hose 6 in the usual manner. An elongate strip of abrasive paper 7 is secured to the bottom of the plate 2 by means of clamps Sand 9 disposed, respectively, on the plate upper surface at the fore and aft ends of the plate.

Those skilled in the art will observe that the long edges 10 and ll of the plate 2 are bent slightly upwardly leaving an unbent central portion of the plate in contrast to the prior art plates which are generally planar. The angled edges 10 and 11 permit the operator to move the assembly transversely into concave areas without digging into the curved surface.

FIG. 2 is an end view illustrating, in more detail, an asymmetrical embodiment of the invention. As shown in FIG. 2, a metal plate 12 overlays a layer 13 of resilient material such as rubber for cushioning the abrasive paper, not shown in FIG. 2. The layer 13 is permanently bonded to the lower surface of the plate 12 by a suitable cement. The two edges of the plate 12 are angled upwardly, respectively, at the bend areas 14 and about a radius 15. It will be observed that the bend 14 is at at an obtuse angle while the radius 15 sweeps about a angle. This asymmetrical configuration permits substantial versatility to the operator in preparing areas with both relatively shallow and relatively steep curvatures. By reversing the plate 12 on the power head 1, the operator can adapt the assembly to the arrangement best suited to the job at hand according to whether he is left handed or right handed and whether the area of maximum curvature is to the right or left as he utilizes the assembly.

FIG. 3 illustrates a configuration for a metal plate 16 which is very satisfactory for general work including slightly concave areas. The abrasive paper, not shown in FIG. 3, is held in place by the clamp 8, and a resilient layer 17, equivalent to the layer 13 of FIG. 2, is disposed beneath the metal plate 16. Equal, shallow bends 18 and 19 raise the outer edges of the plate 16 for the purpose previously alluded to. By way of example, it has been found that an angle of the bends 18 and 19 may be on the order of 7 although it will be understood that the invention contemplates a range of angles between approximately 7 and 90 selected according to the work piece at hand.

While the principles of the invention have now been made clear in an illustrative embodiment, there will be immediately obvious to those skilled in the art many modifications of structure, arrangement, proportions, the elements, materials, and components, used in the practice of the invention which are particularly adapted for specific environments and operating requirements without departing from those principles.

lclaim:

1. An attachment for a power sander utilizing an elongate strip of abrasive paper comprising:

A. a generally rectangular metal plate having first and second opposed parallel long edges, first and second opposed, parallel short edges, and upper and lower surfaces;

B. a layer of resilient material bonded to and completely covering said lower face;

form outwardly directed, equal obtuse angles with respect to said unbent portion of said plate.

3. The attachment of claim 1 in which said first bend forms an outwardly directed obtuse angle and said second bend forms an outwardly directed acute angle, each with respect to said unbent portion of said plate.

4. The attachment of claim 3 in which said second bend sweeps about a radius and extends to said second edge. 

1. An attachment for a power sander utilizing an elongate strip of abrasive paper comprising: A. a generally rectangular metal plate having first and second opposed parallel long edges, first and second opposed, parallel short edges, and upper and lower surfaces; B. a layer oF resilient material bonded to and completely covering said lower face; C. first and second clamps disposed on said upper surface proximate, respectively, said first and second short edges for securing the ends of the abrasive paper strip beneath said layer of resilient material; and D. first and second upward bends in said plate parallel to and inboard from, respectively, said first and second long edges leaving an unbent portion therebetween.
 2. The attachment of claim 1 in which said bends form outwardly directed, equal obtuse angles with respect to said unbent portion of said plate.
 3. The attachment of claim 1 in which said first bend forms an outwardly directed obtuse angle and said second bend forms an outwardly directed acute angle, each with respect to said unbent portion of said plate.
 4. The attachment of claim 3 in which said second bend sweeps about a radius and extends to said second edge. 